<template>
  <div class="slide-verify" id="slideVerify" :style="widthlable" onselectstart="return false;">
    <canvas :width="w" :height="h" ref="canvas"></canvas>

    <canvas :width="w" :height="h" ref="block" class="slide-verify-block"></canvas>
    <div @click="refresh" class="slide-verify-refresh-icon"></div>
    container -->
    <div class="slide-verify-slider" :style="widthlable"
         :class="{'container-active': containerActive, 'container-success': containerSuccess, 'container-fail': containerFail}">
      <div class="slide-verify-slider-mask" :style="{width: sliderMaskWidth}">
        <!-- slider -->
        <div @mousedown="sliderDown"
             @touchstart="touchStartEvent"
             @touchmove="touchMoveEvent"
             @touchend="touchEndEvent"
             class="slide-verify-slider-mask-item"
             :style="{left: sliderLeft}">
          <div class="slide-verify-slider-mask-item-icon"></div>
        </div>
      </div>
      <span class="slide-verify-slider-text">{{ sliderText }}</span>
    </div>
  </div>
</template>

<script>
const PI = Math.PI

function sum (x, y) {
  return x + y
}

function square (x) {
  return x * x
}

export default {
  name: 'SlideVerify',
  props: {
    // block length
    l: {
      type: Number,
      default: 42
    },
    // block radius
    r: {
      type: Number,
      default: 10
    },
    // canvas width
    w: {
      type: Number,
      default: 310
    },
    // canvas height
    h: {
      type: Number,
      default: 155
    },
    block_x: {
      type: Number,
      default: 155
    },
    block_y: {
      type: Number,
      default: 20
    },
    sliderText: {
      type: String,
      default: 'Slide filled right'
    },
    imgurl: {
      type: String,
      default: ''
    },
    miniimgurl: {
      type: String,
      default: ''
    }

  },
  data () {
    return {
      containerActive: false, // container active class
      containerSuccess: false, // container success class
      containerFail: false, // container fail class
      canvasCtx: null,
      blockCtx: null,
      block: null,
      canvasStr: null,
      // block_x: undefined, // container random position
      // block_y: undefined,
      L: this.l + this.r * 2 + 3, // block real lenght
      img: undefined,
      originX: undefined,
      originY: undefined,
      isMouseDown: false,
      trail: [],
      widthlable: '',
      sliderLeft: 0, // block right offset
      sliderMaskWidth: 0 // mask width
    }
  },
  mounted () {
    // 随机生成数this.block_x =
    this.init()
    // console.log(this.imgurl)
    // console.log(this.miniimgurl)
    // console.log(this.block_y)
    // console.log(this.block)
    // console.log(this.canvasStr)
    // console.log(this.canvasCtx)
    // console.log(this.blockCtx)
  },
  methods: {
    init () {
      this.initDom()
      this.bindEvents()
      this.widthlable = 'width:' + this.w + 'px;'
      this.initImg(100)
    },
    initDom () {
      this.block = this.$refs.block
      this.canvasStr = this.$refs.canvas
      this.canvasCtx = this.canvasStr.getContext('2d')
      this.blockCtx = this.block.getContext('2d')
    },
    initImg (h) {
      const img = document.createElement('img')
      img.onload = onload
      console.log(img)
      img.onerror = () => {
        img.src = this.imgurl
      }
      // console.log(img)
      img.src = this.imgurl
      console.log(src)
      img.onload = function () {
        this.canvasCtx.drawImage(img, 0, 0, this.w, this.h)
      }

      this.img = img
      const img1 = document.createElement('img')
      var blockCtx = this.blockCtx
      var block_y = h || this.block_y
      img1.onerror = () => {
        img1.src = this.miniimgurl
      }
      img1.src = this.miniimgurl
      img1.onload = function () {
        blockCtx.drawImage(img1, 0, block_y, 61, 61)
      }
    },
    refresh () {
      this.$emit('refresh')
    },
    sliderDown (event) {
      this.originX = event.clientX
      this.originY = event.clientY
      this.isMouseDown = true
    },
    touchStartEvent (e) {
      this.originX = e.changedTouches[0].pageX
      this.originY = e.changedTouches[0].pageY
      this.isMouseDown = true
    },
    bindEvents () {
      document.addEventListener('mousemove', (e) => {
        if (!this.isMouseDown) return false
        const moveX = e.clientX - this.originX
        const moveY = e.clientY - this.originY
        if (moveX < 0 || moveX + 38 >= this.w) return false
        this.sliderLeft = moveX + 'px'
        const blockLeft = (this.w - 40 - 20) / (this.w - 40) * moveX
        this.block.style.left = blockLeft + 'px'

        this.containerActive = true // add active
        this.sliderMaskWidth = moveX + 'px'
        this.trail.push(moveY)
      })
      document.addEventListener('mouseup', (e) => {
        if (!this.isMouseDown) return false
        this.isMouseDown = false
        if (e.clientX === this.originX) return false
        this.containerActive = false // remove active
        this.verify()
      })
    },
    touchMoveEvent (e) {
      if (!this.isMouseDown) return false
      const moveX = e.changedTouches[0].pageX - this.originX
      const moveY = e.changedTouches[0].pageY - this.originY
      if (moveX < 0 || moveX + 38 >= this.w) return false
      this.sliderLeft = moveX + 'px'
      const blockLeft = (this.w - 40 - 20) / (this.w - 40) * moveX
      this.block.style.left = blockLeft + 'px'

      this.containerActive = true
      this.sliderMaskWidth = moveX + 'px'
      this.trail.push(moveY)
    },
    touchEndEvent (e) {
      if (!this.isMouseDown) return false
      this.isMouseDown = false
      if (e.changedTouches[0].pageX === this.originX) return false
      this.containerActive = false
      this.verify()
    },
    verify () {
      const arr = this.trail // drag y move distance
      const average = arr.reduce(sum) / arr.length // average
      const deviations = arr.map(x => x - average) // deviation array
      const stddev = Math.sqrt(deviations.map(square).reduce(sum) / arr.length) // standard deviation
      const left = parseInt(this.block.style.left)
      this.$emit('success', left)
    },
    reset (h) {
      this.containerActive = false
      this.containerSuccess = false
      this.containerFail = false
      this.sliderLeft = 0
      this.block.style.left = 0
      this.sliderMaskWidth = 0
      this.canvasCtx.clearRect(0, 0, this.w, this.h)
      this.blockCtx.clearRect(0, 0, this.w, this.h)
      this.initImg(h)
    }
  }
}
</script>

<style lang="less" scoped>
.slide-verify {
  position: relative;
  width: 310px;
}

.slide-verify-block {
  position: absolute;
  left: 0;
  top: 0
}

.slide-verify-refresh-icon {
  position: absolute;
  right: 0;
  top: 0;
  width: 34px;
  height: 34px;
  cursor: pointer;
  background: url("../../../public/image/1.jpg") 0 -437px;
  background-size: 34px 471px
}

.slide-verify-slider {
  position: relative;
  text-align: center;
  width: 310px;
  height: 40px;
  line-height: 40px;
  margin-top: 15px;
  background: #f7f9fa;
  color: #45494c;
  border: 1px solid #e4e7eb
}

.slide-verify-slider-mask {
  position: absolute;
  left: 0;
  top: 0;
  height: 40px;
  border: 0 solid #1991FA;
  background: #D1E9FE
}

.slide-verify-slider-mask-item {
  position: absolute;
  top: 0;
  left: 0;
  width: 40px;
  height: 40px;
  background: #fff;
  box-shadow: 0 0 3px rgba(0, 0, 0, 0.3);
  cursor: pointer;
  transition: background .2s linear
}

.slide-verify-slider-mask-item:hover {
  background: #1991FA
}

.slide-verify-slider-mask-item:hover .slide-verify-slider-mask-item-icon {
  background-position: 0 -13px
}

.slide-verify-slider-mask-item-icon {
  position: absolute;
  top: 15px;
  left: 13px;
  width: 14px;
  height: 12px;
  background: url("../../../public/image/1.jpg") 0 -26px;
  background-size: 34px 471px
}

.container-active .slide-verify-slider-mask-item {
  height: 38px;
  top: -1px;
  border: 1px solid #1991FA;
}

.container-active .slide-verify-slider-mask {
  height: 38px;
  border-width: 1px;
}

.container-success .slide-verify-slider-mask-item {
  height: 38px;
  top: -1px;
  border: 1px solid #52CCBA;
  background-color: #52CCBA !important;
}

.container-success .slide-verify-slider-mask {
  height: 38px;
  border: 1px solid #52CCBA;
  background-color: #D2F4EF;
}

.container-success .slide-verify-slider-mask-item-icon {
  background-position: 0 0 !important;
}

.container-fail .slide-verify-slider-mask-item {
  height: 38px;
  top: -1px;
  border: 1px solid #f57a7a;
  background-color: #f57a7a !important;
}

.container-fail .slide-verify-slider-mask {
  height: 38px;
  border: 1px solid #f57a7a;
  background-color: #fce1e1;
}

.container-fail .slide-verify-slider-mask-item-icon {
  top: 14px;
  background-position: 0 -82px !important;
}

.container-active .slide-verify-slider-text,
.container-success .slide-verify-slider-text,
.container-fail .slide-verify-slider-text {
  display: none;
}
</style>
